Range finder for cameras



Nov. 13, 1945. H SCHWARTZ ET 2,388,714

RANGE FINDER FOR CAMERAS Original Filed Nov. 24, 1941 3 Sheets-Sheet 1 INVEN CR5 ATTORNEY 1945- H. SCHWARTZ ETAL RANGE FINDER FOR CAMERAS Original Filed Nov. 24, 1941 3 Sheets-Sheet 2 lNV TORS wart} tea e110 ATTORN Nov- 13, 1945- H. scHwARTz ETAL RANGE FINDER FOR CAMERAS 3 Shets-Sheet 3 Original Filed Nov; 24, 1941 Patented Nov. 13, 19 45 UNITED STATES PATENT OFFICE RANGE FINDER FOR CAMERAS Hyman Schwartz and William Castedello, Stamford, Conn., assignors to The Kalart Company, Inc? New York, N. Y., a corporation of New Yor Substituted for abandoned application Serial No. 420,158, November 24, 1941. This application January 2'7, 1943, Serial No. 474,048

9 Claims. (Cl. 9544) The present invention relates primarily to of the camera at the object to be photographed photographic devices and more particularly to when the light conditions are such as to preclude a device whereby the proper focusing of a camthe usual aiming of the camera with a view finder era may be effected when the light conditions or or ground glass. the degree of illumination is insufficient and such These and still other objects of the invention as to preclude the satisfactory use of the usual will be more apparent hereinafter in the detailed focusin or measuring arrangements such as disdescription thereof wherein reference is made tance scales, ground glasses, range finders, or to the accompanying drawings, in which: view finders. Fig. 1 is a side elevational view of a camera The present application is a substitute applicawith a range finder attached thereto, partly in tion for the application filed November 24, 1941, section, showing the operating position of the bearing Serial No. 420,158. light producin unit of the present invention One of the prerequisites for taking good picrelative thereto; tures with sharp definition is to have the camera Fig. 2 is a plan view of the camera taken subproperly focused which includes positioning the stantially on line 2-2 of Fig. 1, showing a range lens of the camera the proper distance in front finder, a photofiash unit, and the manner in of the negative film. The positioning of a parwhich they co-operate with the device of the ticular lens relative to the negative for sharp present invention;

definition varies and is a function within prede- Fig. 3 is a rear elevational view of the eletermined limits of the distance of the object to ments of Fig. 2; be photographed from the camera. Devices such Fig. 4 is a vertical sectional view taken substanas distance scales, range finders, view finders, tially on line 4-4 of Fig. 2;

and so forth, have been developed which while Fig. 5 is a front detailed view of the light pro-' assisting in the proper focusing and aiming of a ducing unit of the present invention; camera require for their satisfactory operation a Fig. 6 is a sectional view taken substantially certain minimum degree of illumination and do through the center of the light producing unit;

not function satisfactorily unless at least the Fig. 7 is a sectional view taken substantially minimum amount of illumination is present. on line 1-1 of Fig. 6;

Accordingly, it is one of the primary objects Figs. 8 and 9 are diagrammatic views illustratof the present invention to provide a device which 0 ing the principles of operation of the present inenables the use of measuring arrangements, such vention;

'as range finders, under light conditions which Fig. 10 is a wiring diagram showing the elecwould preclude the use of the range finder withtrical connections between the light producing out the device. unit, the photofiash unit battery, the photofiash Another object of the present invention is to lamp, and the various switches;

provide a device which will co-operate with a Fig. 11 is a rear elevational view. showing a range finder and enable the use thereof under modified arrangement of the invention;

dark conditions and which may readily be ar- Fig. 12 is a sectional view taken on line l2-l2 ranged to permit the use of the range finder in of Fig. 11;

the normal manner under normal light condi- Fig. 13 is a sectional view-taken on line l3l3 tions. of Fig. 11;

Still another object of the invention is to pro- Fig. 14 is a sectional view of the lower part of vide a device which may readily be attached to the casing of the photofiash unit; and a photofiash bulb unit or apparatus to be oper- Fig. 15 is a wiring diagram of the electrical ated by the battery included therein'when the connections between the various units as emsame is used in conjunction with a camera. ployed in the modified arrangement of the in- Still another object of the invention is to provention. vide a device which while using current from Referring first to Figs. 1 and 2, 9. camera,1nd1 the battery of a photofiash unit during the opcated in general by reference numeral 2|, is eration thereof and the determining of the range shown in its open condition. The camera comof the object to be photographed is automatically prises a casing 22, a bed 23, and a lens board or disconnected from the battery when in a nonsupport 24 movable toward and away from the operating position, focal plane to correctly position a lens 26 car- Still another object of the invention is to proried therein the proper distance in front of the vide a device which assists in the proper aiming sensitized film in the camera when focusing the same. The movement of the lens support 24 back and forth along the camera bed 23 is accomplished by means of racks 21 which engage pinions (not shown) rotated by means of focusing knobs 28. Movable in and out with the lens support 24 is a bracket 29 attached to the movable track element on the camera bed which carries adjacent its upper end an eccentric shoulder screw 31. Engageable with the shoulder screw 3| is the lower end of a coupling lever 32 which controls a range finder indicated in general by reference numeral 33 attached to the left hand side of the camera casing 22 as viewed from the front of the camera.

The camera 2|, shown in the drawings, is of the type known in the art as a Speed Graphic and the range finder 33 is preferably of the type disclosed in a copending application of M. Schwartz and W. Castedello, Ser. No. 418,516, filed November 10, 1941, and although the invention is shown and hereinafter described as co-operating with this type of camera and'range finder, it will be obvious hereinafter that the invention is not limited in its application to these particular range finder and camera units but may be applied to various other types of cameras employing coupled range finders.

The range finder 33 includes a stationary silverflecked mirror 34 mounted at an angle of approximately 45 and a pivotable mirror 36 in the lower part of the range finder which is pivoted in accordance with a predetermined relationship to the position of the lens 26. The manner of pivoting the movable mirror 36 in accordance with the position of the lens 23 is fully described in the above mentioned copending application. The coupling lever 32 controls the pivoting of the mirror 36 during a predetermined part of the movement of the lens support 24 or until the shoulder screw 3| is moved sufiiciently to be disengaged from the lever 32. Located in the upper part of the range finder casing in line with the silverfiecked mirror 34 is a rear window 31 and a front window 38. A lower front window 39 is also supported in the casing of the range finder opposite the movable mirror 36.

In the normal use of the range finder, the object to be photographed is sighted through the rear or left hand window 31, Fig. 1, the silverfiecked mirror 34 and the window 38. At the same time an image of the object is also reflected from the movable mirror 36 and the back of the silver-decked mirror 34 through the rear or left hand window 31 to the eye. When the lens support 24 is so positioned to control the range finder so that the object viewed directly and the image thereof as reflected from the movable mirror 36 are superimposed on each other, the camera lens is at the proper position relative to the camera casing or the camera is properly focused on the object. or course, the range finder has to be synchronized with the camera lens 26 in order to obtain the proper focus, the adjustments for properly synchronizing the range finder with the particular lens in the camera being fully described in the above-mentioned copending application.

Also attached to the camera by means of screws such as 4| is-a photoflash unit bracket 42. The bracket 42, best shown in Figs. 2 and 3, has sections 43 and 44 thereof extending on either side of the range finder adjacent the windows 38 and 31, respectively, in the upper end thereof. Openings or holes 46 are formed in the sections 43 and 44 of the bracket 42 in order to permit a clear view through the windows 31 and 38. At-

tached to the vertical section of the bracket 42 by means of a clamping mechanism indicated in general by reference numeral 41 is a photoflash unit 48. The photoflash unit includes a battery casing 49, the reflector 5i and various other ele-' ments hereinafter described. Attached to the battery casing 69 by means of screws such as 52 is a band 33 which surrounds the battery casing and forms a part of the clamping mechanism 31.

Secured to the band 53 above the clampin mechanism 41 by means of screws 36 i a block 51, Figs. 2, 3 and 4, composed of insulating material such as Bakelite, to which is connected electrical conductors 53 and 33. The two conductors 53 and 59 are formed into a cable 68 and are connected to the battery casing by means of a plug 65. One of the conductors such as 53 is connected to one of the poles of the battery in the battery casing 49 while the other conductor such as 59 is connected through a switch such as 3! to the oppostie pole of the battery. The ends of the conductors 58 and 59, Fig. 4, which terminate in the insulating block 51 are electrically connected to a sleeve 62 and a pin 63 respectively. The sleeve 62 is recessed in the block 51 and the pin 63 protrudes therefrom. A spring (not shown) is associated with the pin 63 and normally tends to keep the pin in an extended position, the spring permitting the pin to be pushed into the block 51. Also extending from the block 51 is a fiat-headed screw 64 and a stop pin 63.

Adapted to be associated with the block 51 and electrically connected to the conductors 58 and 59 in a manner hereinafter described is a light unit indicated in general by reference numeral 31, Figs. 3, 5 and 6. The light unit 61 is square in cross-section and has a pin 68 extending therefrom adapted to be inserted in the sleeve 52 on the block 51. Formed on the pin is a flanged shoulder 39 which has a notch 11 therein, Figs. 4 and 5, which co-operates with the head of the screw 64 to lock the light unit to the block in a manner hereinafter pointed out.

The casing of the light unit 61 is of metal and secured to the right end thereof is a collar 12. The collar 12 has a circular hole therein substantially the same in diameter as the inside dimension of the casing 10 of the light unit 31. Adapted to fit into the light unit casing 31 through the hole in the collar 12 is a sleeve 13. The right hand end of the sleeve 13, as shown in Fig. 6, has a piece of Bakelite or similar insulating material 14 extending therein to approximately the longitudinal center thereof. The Bakelite cylinder 1 3 is forced into the sleeve 13 so as to be movable therewith. The left hand end of the sleeve 13 is slightly less in diameter than the main portion thereof and has slots such as 16 formed axially thereof. The slots 1G enable the sleeve 13 to hold a small bulb 11 of the type employed in flashlights in the left hand end of the sleeve. Extending through the Bakelite cylinder 14 is a *rod 18, Fig. 7, which contacts the center tip of ed into the casing of the light unit clamps the sleeve I3 in its adjusted position.

In attaching the light unit 61 to the block 51 on the battery casing, the pin 68 on the light unit is inserted part way in the sleeve 62 in the block 51. The unit is then positioned at an an- I gle of about 45 to the right'with the notch 'II in the flanged shoulder 69 of the pin in line with the head of the screw 64. With the light unit in this position the pin 68 may be inserted the full depth in the sleeve 62 or until the face of. the shoulder 63 abuts the Bakelite block 51 as shown in Fig. 2. The head of the screw 64 is not seated against the block 51 but is spaced a slight distance therefrom substantially equal to the thickness of the shoulder 69. With the pin 68 inserted in the sleeve the full depth thereof the light unit 61 may be pivoted about the pin in a counter-clockwise direction as shown in Fig. 3. The flanged part of the shoulder 69 passes underneath the head of the screw 64 to lock the same to the block 51 and prevents removal of the light except when the said unit is in a position of approximately 45 to the right.

The collar I2 as shown in Fig. 7 has a notch 82 therein and when the light unit is pivoted on the pin 68 to a position such as that shown in Figs. 2 and 3, the notch 82 engages the stop pin 66 to prevent further pivoting of the light unit in a counter-clockwise direction, and in this position the axis of the light unit is substantially horizontal. Just before the light unit 61 is pivoted into its horizontal position, as shown in Fig. 3, the disc I9 on the right hand end thereof moves into operative relation with the spring-pressed pin 83 to establish an electrical connection between the pin and the disc. The establishing of the electrical connection completes a circuit between the two conductors 58 and 59 through the bulb II in the light unit, the disc I9 being in electrical connection with the center terminal of the bulb through the rod I8 and the pin 68 being in electrical connection with the other terminal of the bulb through the sleeve I3. With such an arrangement the bulb can be lighted only in or near its operative position and such an arrangement is very advantageous as it prevents unnecessary use of the battery in the battery casing 43 and also prevents undesirable illumination of the object to be photographed which is a desirable feature especially if time exposures are being made.

Secured to the casing of the light unit 61 adjacent the left hand end thereof as shown in Figs, 5 and 6 is a lens holder 83 which contains a lens 84. The lens 84 and holder 83 are axially positioned relative to a hole 86 in the casing lo- 'cated directly abov a mirror IiI supported on a block 88. The mirror is positioned at an angle of approximately 45 as shown in Fig. 6 so as to reflect light from thelbulb 17 through the hole 86 and lens 84.

In the operation of the invention the light from the bulb 1I shines into the range finder 33 and part of the light beam passes'through the stationary silver-necked mirror 34, Fig. 1, directly to the object to be photographed, while the rest of the light beam is reflected from the mirror 34 down onto the movable mirror 38 and then out through the window 33 in the direction of the object to be photographed. Figs. 8 and 9 illustrate diagrammatically the manner in which the two light beams are projected from the range finder 33. In Fig. 8 the two light beams 83 and 9| are directed to different positions on the object 92. Movement of the lens support 24 of the camera pivots the movable mirror 36 and when the lens support is positioned and the mirror 36 so pivoted that the two beams and SI are directed to a single spot on the object 92, as in Fig. 9, the lens will be at the proper distance with respect to the negative in the camera for an object located such a distance from the camera. Thus all that is necessary when it is desired to photograph an object is to project the two light beams from the range finder and move the lens of the camera either in or out as the case may be until the two beams are directed to but a single spot on the object. With the lens of the camera properly synchronized with the range finder, the two beams of light from the range finder coincide at a point a given distance from the camera which is proportional to or a function of the distance between the lens and the negative. By this arrangement focusing of the camera. may be properly effected where the light conditions are such as to prevent the normal focusing thereof, and such an arrangement has an obvious advantage in that illumination of the object to the degree required for the use of the normal measuring arrangements is not necessary. Another advantage is that the upper light beam is substantially parallel to the axis of the camera lens so that the camera is aimed at substantially the same spot as the upper light beam.

Fig. 10 illustrates the electrical connections in the apparatus shown in the first embodiment of the invention, wherein a battery 93 employed to ignite the photoflash bulb 94 on closing of a switch 96 is also employed to illuminate the light bulb IT. The closing of the switch 6| completes a circuit from on pole of the battery 93 through the bulb 'I'I back to the other pole of the battery. The pin 63, Figs. 2, 4 and 10, constitutes an auxiliary safety switch which prevents illumination of the bulb II in a non-operative position of the light unit 61.

The second modification of the invention as shown in Figs. 11 to 15 has certain advantages over the first modification shown in Figs. 1 to 10. In the second modification, Figs. 11 to 15, the battery casing 91 is attached to the bracket 42 surrounding the range finder 33 by means of a clamping mechanism indicated in general by reference numeral 98. The clamping mechanism 98 includes a lever 99 which releases the battery casing for removing the same from the bracket 42. The clamping mechanism also includes a band IOI surrounding the battery casing 91 which holds the battery casing in position. Attached to the band IOI by screws such as I02, Fig. 12, is a block of insulating material I03. A metal sleeve I04 in the block I03 is connected by means of a compression spring I06 in the inner end thereof to a metal strap I01 which at its lower end is connected to one of the poles of the battery in the casing 9'1. The casing 91 is of insulating material such as Catalin, and an electrical connection between the bottom of the battery cells, as shown in Fig. 14, to the upper end of the battery casing is by means of the metal strap W1. A pin I09 with a shoulder on the inner end thereof is carried in the block I03 and connected by means of a compression spring III to the lower end of .another metal strap I08 inside the casing 91. The

applied thereto and when the light unit 81 is mounted on the block I03 in the same manner as it is mounted on the block 51 in the first embodiment of the invention, the bulb 11 therein will be in an electric circuit which includes the battery. With the arrangement shown in Figs. 11 to 15, no outside electrical connection is required to the light unit 61 such as the cable containing the conductors 58 and 59 in the first embodiment, and the second embodiment obviously has an advantage over the first embodiment. The compressible pin I09 in the block I03 permits the completion of a circuit to the bulb 11 in the light unit only just before and when the unit is in an operative position or the position with the lens 84 therein substantially opposite the sighting window of the range finder 33. The light unit 61 is locked and positioned on the block H13 in the second modification in the same manner as it is attached to the block 51 in the first modification.

The embodiment shown in Figs. 11 to 15 also includes a synchronizing unit indicated in general by reference numeral I I2 which may be of the type disclosed in a copending application of M. Schwartz et al., Ser. No. 403,819, filed July 24, 1941, now Patent No. 2,321,945 dated June 15, 1943, which synchronizes the peak combustion of the photofiash bulb H3 with the operation of the camera shutter. The unit H2 is attached to the upper end of the battery casing 91 just below an auxiliary switch HA which permits ignition of the photoflash bulb II3 independently of the shutter tripping. The photofiash bulb has associated therewith a reflector I I6 which is attached to the battery casing 91 by means of a spring member 1 extending through a bracket 8 on the upperend of the battery casing.

The electrical connections of the second embodiment of the invention are shown in Fig. 15 wherein potential from the battery 93' is connected by means of the pin I03 to the disc 19 of the light unit and through the bulb 11 to the other pole of the battery. The switch H4 and the switch H9 in the flash unit H2 are in parallel and control the circuit to the flash bulb I I3.

Another advantage of the second embodiment is that no operating switch is employed in the circuit to the bulb 11, the circuit to the bulb 11 being completed when the light unit is moved to its operative position and the circuit being broken when the light unit is in any other position. This arrangement eliminates the necessity of wire and cable connections to the light unit which are a source of potential failure.

It is obvious, of course, that various other modiflcations of the invention may be made without departing from the spirit or essential attributes thereof and it is desired, therefore, that only such limitations be placed thereon as are imposed by the prior art or are specifically set forth in the appended claims.

What is claimed is:

1. In combination with a camera having a focusing lens movable relative to the casing thereof, a range finder having a sighting window and two objective windows, said range finder being controllable in a predetermined manner by the focusing movement of said lens, a photofiash unit including a battery, a light unit including a light bulb conne'ctable with said battery, means for pivotally moving said light unit into operative relation with the sighting window of said range finder whereby a beam of light from said bulb may be directed into said range finder through said sighting window, a stop for limiting pivotal movement of said light unit when in position to direct the light beam into said. range finder through the sighting window thereof, means in said range finder for dividing said beam of light into two separate beams and directing the same out through the two objective windows of said range finder and means including the control of said range finder by the movement of said focusing lens whereby the two light beams merge at the focal point of said lens relative to the position thereof with respect to the camera negative.

2. The combination as set forth in claim 1 and means including the movement of said light unit into operative relation with said sighting 'window to complete a circuit to the light bulb therein from said battery.

3. The combination as set forth in claim 1 and an electrical circuit between said battery and said bulb in said light unit, a safety switch and a manually operable switch in series relation in said circuit and means controlled by the position of said light unit for closing said safety switch only when in operative relation with said sighting window whereby the operation of said manually operable switch is ineffective to complete a circuit from said battery to said bulb with said light unit in any other position.

4. The combination of a range finder of the type described and a light unit for producing a beam of light for use in conjunction with said range finger, a pin and a cooperating recess for supporting said light unit in spaced relation relative to said range finder, said pin and recess permitting removal of said light unit from association with said range finder, an electric bulb in said light unit, means for pivoting said light unit on said pin to move the same into and outof position to direct the beam of light therefrom into said range finder, and means for completing a circuit to the bulb in said light unit only when the same is substantially in position to direct a beam of light therefrom into said range finder.

5. The combination of a range finder of the type described and a light unit for producing a light beam for use in conjunction with said range finder, a pin projecting from said light unit, a

member fixed relative to said range finder and adapted to receive said pin whereby said light unit is pivotally mounted, a source of potential for the light bulb in said light unit, means including said pin for establishing a circuit from one terminal of said source to a terminal of said bulb and means operative with said pin in said member and said light unit pivoted into predetermined relationship with said range finder to complete a circuit from the other terminal of said source to the other terminal of said bulb whereby the same is illuminated to produce a light beam for use in conjunction with said range finder.

6. The combination of a range finder of the type described and a light unit for producing a light beam for use in conjunction with said range finder, a pin projecting from said light unit, a light unit mounting member fixed relative to said range finder and having a recess adapted to receive said pin, said pin and recess enabling said light unit to pivot relative to said mounting member and range finder; a flanged element on said light unit concentric with said pin and having a notch therein, a headed element on said mounting member and co-operating with said flanged element to permit insertion of said pin in said member greater than a predetermined distance only with said light unit in a predetermined pivoted position relative thereto and to lock said assaria light unit to said mounting member on the pivoting thereof after the insertion of said pin in said member a still further predetermined amount.

7. The combination or a range finder of the type described and a light unit for producing a light beam for use in conjunction with said range finder, a pin projecting from said light unit, a light unit mounting member fixed relative to said range finder and having a recess adapted to receive said pin, said pin and recess enabling said light unit to pivot relative to said mounting memher and range finder, means for enabling inserthan of said pin in said member a predetermined distance only with said light unit in a predetermined pivoted position relative thereto, means operative after the insertion of said pin in said mounting member said predetermined distance and the pivoting thereof relative to said mounting member to lock the same thereto, a source of potential for the bulb in said light unit and means for completing a circuit from said source to said bulb to illuminate the same only with said light unit locked to said mounting member.

8. The combination of a range finder of the type described and a light unit for producing a light beam for use in conjunction with said range finder, a support for said light unit, said unit and support having a pin and a cooperating recess whereby said unit is pivotable relative to said support about a point spaced from the sighting window of said range finder and whereby said unit is movable to direct the light beam from the same into said sighting window, and means for locking said pin in said recess and said light unit to said support when pivoted to the position for directing the light beam therefrom into said range finder.

9. The combination of a range finder of the type described and a light unit for producing a light beam for use in conjunction with said range finder, a support for said light unit, said unit and support having a pin and a cooperating recess whereby said unit is pivotable relative to said support abouta point spaced from the sighting window of said range finder and whereby said unit is movable to direct the light beam from the same into said sighting window, a source of potential for the light producing element in said light unit, means including said pin and recess for establishing a circuit from one terminal 0! said source to said light producing element and means operative to complete a circuit from the other terminal of said source to said light producing element only when said light unit is locked to said support and substantially only in position to direct the light beam therefrom into said range finder.

WILLIAM CASTEDELLO. HYMAN SCHWARTZ. 

